The goal of this multimethod, multireporter, prospective study is to determine if, when, and why students' positive and negative emotions are concurrently and prospectively related to their relationship with their teacher, social competence, problem behaviors, classroom engagement, and subsequent learning and achievement. A fuller understanding of these relations is critical because the knowledge can be used in prevention and intervention programs to precisely target aspects of socioemotional competence that likely positively impact learning and achievement. The first aim is to document the concurrent and prospective relations between children's positive and negative emotions and their achievement. The second aim is to investigate the potential moderating influences of students' own self-regulatory skills and their peers' emotionality and self-regulation on the relations between students' emotion and academic achievement. Aim three is designed to identify processes that might mediate the relations between children's emotions and their achievement, including students' relationships with their teachers and their adjustment and their motivation versus avoidance towards, and engagement in, classroom activities. Observations of various emotions in two contexts (classroom and peer) will allow for the consideration of varying mediating pathways based on the type of emotion and where it is expressed. The aims will be examined in the context of a three-year longitudinal study. Three hundred children will be followed from Kindergarten to 2nd grade. Each year, parents and teachers will report on students' positive and negative emotions, self-regulation, relationships with teachers, social competence, problem behaviors, and engagement. Teachers will report on peers' emotionality, self-regulation, and students' achievement. Children will participate in tasks that assess their positive and negative emotions, their regulation, and their academic achievement. Students' emotions will be observed while they interact with peers during recesses and during class time, while their engagement will be observed throughout the school day. Multivariate, longitudinal analyses will be used to examine prospective direct, mediated, and moderated relations.